1. Field of the Invention
The invention relates to an emergency calling system. The system includes a vehicle station which detects its location and transmits information on its location and a Mayday center which performs two-way communication with the vehicle station and which monitors the two-way communication.
2. Description of the Related Art
Various types of equipment have been installed on vehicles to secure safer running. However, no matter how safety is improved, some accidents will still occur. Or, an occupant of a vehicle might suddenly become ill. In case of such an emergency, it would be desirable to quickly and accurately make an emergency call to concerned agencies or sources of help.
Under such circumstances, Japanese Patent Laid-Open Publication No. Hei 6-20191 proposes a system which, in case of an accident, automatically transmits a driver's location to an emergency contact, such as a fire department, and which also intermittently sends the location of a vehicle to an emergency contact if there is felt to be a risk that an emergency situation might occur. This system is designed so that an emergency contact can presume the occurrence of an accident even if an emergency calling device is disabled due to an accident and can also know the location of the vehicle. This publication also discloses that a plurality of emergency contacts are given an order of priority and emergency calls are performed in that order.
Japanese Patent Laid-Open Publication No. Hei 6-36185 proposes a system that when an accident occurs outside an area communicable with an emergency contact address, an emergency call is made to another vehicle by vehicle-to-vehicle communications. According to this system, an emergency call can be made even when an accident occurrs outside the area communicable with the emergency contact address.
The system disclosed in Japanese Patent Laid-Open Publication No. Hei 6-20191 cannot, however, detect the occurrence of an emergency if such an incident occurs outside an area communicable with an emergency contact. The order of priority is predetermined to enable emergency calling, but it is often necessary to select an emergency contact according to the circumstances of the accident or to select a communications method according to the emergency contact. That system has a drawback that it cannot meet such needs.
The system disclosed in Japanese Patent Laid-Open Publication No. Hei 6-36185 has a disadvantage that an emergency call cannot be made if another communicable vehicle is not available and its reliability is therefore poor.